OpenSourcePhysics/tracker — reverse-engineered prompt

Build me a Java desktop app for physics video analysis, like Tracker from Open Source Physics.

I want users to open a video, image sequence, animated GIF, or still image, then analyze motion frame by frame. They should be able to mark points on objects, track their movement over time, set a scale, define coordinate axes, and see useful graphs or data tables for position and motion. It should feel like a teaching and lab tool for students and teachers doing mechanics experiments from real footage.

Use the Open Source Physics framework if needed, and include the basics so it can run as a normal desktop Java app. If video support needs an extra engine, make the app still work with images and GIFs when that engine is missing, and document what has to be installed for full video support.

Please make it clean, usable, and easy to build from the repo. Look up current docs online if you need to.